Accompanying the rising age of hopeful parents is the increasing use of assisted reproductive techniques such as artificial insemination, in vitro fertilization (IVF), gamete intrafallopian tube transfer (GIFT), and the like. Artificial insemination (AI) is the process by which sperm is placed into the reproductive tract of a female for the purpose of impregnating the female by using means other than sexual intercourse. In humans, it is used as assisted reproductive technology, primarily to treat infertility but is also increasingly used to enable women without a male partner to produce children by using sperm provided by a sperm donor. Specifically, in artificial insemination, freshly ejaculated sperm, or sperm which has been frozen and thawed, is placed in the cervix (intracervical insemination or ICI), in the female's uterus (intrauterine insemination or IUI), in the vagina (intravaginal insemination or IVI), or in the fallopian tubes (intratubal insemination or ITI) by artificial means.
The American Society for Reproductive Medicine estimates that the success rate of artificial insemination may be as high as 15 percent each cycle. Although success rates are higher for other forms of fertility treatments, artificial insemination is often one of the first methods used. It is less invasive and less expensive than more complex procedures, such as in vitro fertilization.
Conception, pregnancy and delivery require an intricate and delicate interplay of physiology and anatomy. Implantation and placentation are complex processes involving hormonal, immune, and anatomical changes in the mother and migration and cellular division of the embryo.
Although pregnancy rates following six cycles of AI or one cycle of IVF can be as high as 60%, some recipients fail repeatedly. Various uterine pathologies, such as thin endometrium, altered expression of adhesive molecules and immunological factors, may be the causes for repeated failure.
Spontaneous abortion occurs in 15%-50% of diagnosed pregnancies in women between fifteen and forty-five years of age. The formal definition of recurrent spontaneous abortion is three or more spontaneous abortions. However, the American College of Obstetrics and Gynecology recommends that in women over the age of 35, a thorough workup should be undertaken after two spontaneous abortions. Approximately 3-4% of women are estimated to fit the formal definition of recurrent spontaneous abortion. The risk of pregnancy loss increases from 15-20% in the first pregnancy to 40% after one spontaneous abortion.
Although many pregnancies lost in the first trimester are due to fetal causes; spontaneous abortion, the loss of the products of conception prior to the 20th week of pregnancy, is often a disorder of unknown etiology. It has been theorized that spontaneous abortions are a natural rejection of a fetus with abnormalities incompatible with life; however, this theory has yet to be substantiated.
Risk factors for miscarriage include age, weight and overall health of the woman. The prevalence of spontaneous abortion increases with increasing maternal age, although not with gravidity. The risk begins to increase rapidly at age 35 years. The risk of spontaneous abortion at age 40 is approximately twice that at age 20. As families are planned later and later in life, the frequency of spontaneous abortion will only increase without effective methods of prevention.
Threatened abortion generally presents as cramping and bleeding for which treatment is bed rest. This conservative treatment provides palliative care for the mother but does little to alter the outcome. The use of hormones is generally contraindicated due to the risk of congenital anomalies, including malformation of the vessels of the heart of the embryo and possible genital abnormalities in female offspring.
Preeclampsia and other hypertensive disorders of pregnancy are a leading global cause of maternal and infant illness and death. Symptoms of preeclampsia include hypertension, edema and proteinuria with sudden weight gain, headaches and changes in vision. Preeclampsia can prevent the placenta from getting enough blood which can cause low birth weight and other problems for the baby. Although most women with preeclampsia still deliver healthy babies, some develop eclampsia, a serious condition that threatens the life of the mother and the fetus.
The risk of preeclampsia is higher in women carrying multiple babies, in teenage mothers and in women older than age 40. Typically, preeclampsia occurs in the late 2nd or 3rd trimesters (middle to late pregnancy) though occasionally it occurs earlier. Preeclampsia affects about 5% of all pregnancies.
Mild preeclampsia is conservatively treated with strict bed rest and vigilant monitoring of blood pressure. Progression of the disorder is treated with fluids, antihypertensives and magnesium sulfate but delivery of the fetus provides the only remedy.
In addition to the physical toll of these disorders, the loss of a desired pregnancy takes a tremendous emotional toll on hopeful and expectant parents. Loss of a pregnancy can lead to feelings of inadequacy, hopelessness and guilt which can have a devastating effect on individuals and on a marriage.
New methods and compositions are always needed to reduce risks associated with pregnancy to the health of the mother and fetus. Effective prevention of implantation failure or spontaneous abortion can allow women, especially women at risk, to have successful pregnancies. In particular, effective prevention of these disorders in women who suffer from infertility can allow women, especially women who seek medical care in the form of assisted reproduction like artificial insemination to have successful pregnancies. Prevention of implantation failure during assisted reproduction allows successful pregnancies, reduces the risks to women, and saves time and money.